dfield8 with R2015b on Mac OSX issues?

Question

Roy Berg 2015-9-10

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回答： George Williams 2017-2-17

Is there a better option for first order ODE solving/plotting in Matlab than dfield8? It gives me problems every time I attempt to enter differential equations. My latest issue is as follows:

Reference to non-existent field 'axes'.
Error in dfield8 (line 813)
      aud = get(dud.axes,'UserData');
Error while evaluating UIControl Callback

Any help or better options would be much appreciated.

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John Wolfe 2015-9-11

编辑：Walter Roberson 2015-9-11

在 MATLAB Online 中打开

Roy, I'm having the same problem. Our DiffEq prof wants us to use dfield8, but it is only compatible up to MATlab 7.7 (R2008b). It seems as though someone must have updated the code in the last 7 years since that was new... and Walter, yes, from the rice website. Do you know of any updated versions?

My errors with the 'newest' version of dfield8 is as follows:

"Error using figure
There is no numb property on the Figure class.
Error in dfield8 (line 258)
    dfset = figure('name','dfield8 Setup','numb','off',..."

I found this code, which works but has no GUI or interactive display, you need to enter the equations, limits, and solution curves when calling the .m file:

function dirfield(f,tval,yval)
% dirfield(f, t1:dt:t2, y1:dy:y2)
%   
%   plot direction field for first order ODE y' = f(t,y)
%   using t-values from t1 to t2 with spacing of dt
%   using y-values from y1 to t2 with spacing of dy
%
%   f is an @ function, or an inline function,
%     or the name of an m-file with quotes.
%
% Example: y' = -y^2 + t
%   Show direction field for t in [-1,3], y in [-2,2], use
%   spacing of .2 for both t and y:
%
%   f = @(x,y) y*x
%   dirfield(f, -10:.2:10, -10:.2:10)
%   hold
%   [ts,ys] = ode45(f,[x0,xf],y0) 
%   plot(ts,ys,'k-')
[tm,ym]=meshgrid(tval,yval);
dt = tval(2) - tval(1); 
dy = yval(2) - yval(1);
fv = vectorize(f);
if isa(f,'function_handle')
  fv = eval(fv);
end
yp=feval(fv,tm,ym); 
s = 1./max(1/dt,abs(yp)./dy)*0.35;
h = ishold;
quiver(tval,yval,s,s.*yp,0,'.r'); hold on;
quiver(tval,yval,-s,-s.*yp,0,'.r');
if h
  hold on
else
  hold off
end
axis([tval(1)-dt/2,tval(end)+dt/2,yval(1)-dy/2,yval(end)+dy/2])

Arthur Wasserman 2016-3-3

It would be a great service if someone were to update dfield, pplane, and odesolve for the latest version of Matlab.

Walter Roberson 2016-3-12

It would be a great service, yes -- but performing the service doesn't pay any bills.

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Answer 1

Rick Saltzman 2016-2-13

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https://ww2.mathworks.cn/matlabcentral/answers/242199-dfield8-with-r2015b-on-mac-osx-issues#answer_209705

在 MATLAB Online 中打开

Errors also arise due to the use of:

if notice

and

if dud.notice

These are corrected by:

if ~isEmpty(notice)
if ~isEmpty(dud.notice)

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Nenad Dragojevic 2016-12-15

编辑：Nenad Dragojevic 2016-12-15

Hello, very nice answer, but in Matlab R2015a (Windows7): Undefined function '~isEmpty'!

'~isempty' works for me.

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Answer 2

George Williams 2017-2-17

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https://ww2.mathworks.cn/matlabcentral/answers/242199-dfield8-with-r2015b-on-mac-osx-issues#answer_255228

Gives a good updated version for Matlab R2016b: https://uk.mathworks.com/matlabcentral/fileexchange/61636-pplane?s_tid=srchtitle%2520

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Answer 3

ahmed 2016-6-20

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https://ww2.mathworks.cn/matlabcentral/answers/242199-dfield8-with-r2015b-on-mac-osx-issues#answer_226096

编辑：ahmed 2016-6-20

you will find the both editions in this link (one for Matlab 2014 and before, the other is for Matlab 2015 and later):

https://web.njit.edu/~yyoung/M222Spring2016/M222Spring16.html

Update: the file of pplane8.m which found in this link works for Matlab 2015 and later :)

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sean orourke 2017-2-13

pplane8.m DOES NOT WORK for R2015b

Walter Roberson 2017-2-14

go through and replace every occurrence of 'numb' (the quoted string exactly like that) with 'numbertitle'. . Also replace one 'number' (the quotes string exactly like that) with 'numbertitle'

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